For the frittata: Preheat the oven to 325 degrees F.
In a large ovenproof saute pan over high heat, add the olive oil, onions, sausage, garlic and oregano, stirring frequently to break up the clumps. Add the roasted peppers and cook about 10 minutes.
In a large bowl, whisk together the eggs, cream, feta cheese, smoked salt and pepper. Pour the mixture into the saute pan and bake until the eggs are set and golden brown and the frittata pulls away from the sides slightly, about 35 minutes. Remove the frittata from the oven and let cool about 10 minutes.
For the sauce: In a small bowl, combine the chives, lemon zest and juice, sour cream and olive oil. Season with salt and pepper.
Cut the frittata into pieces and serve with dollop of the sour cream sauce.